key.c 24.5 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922
/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
 * Copyright 2007-2008	Johannes Berg <johannes@sipsolutions.net>
 * Copyright 2013-2014  Intel Mobile Communications GmbH
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/if_ether.h>
#include <linux/etherdevice.h>
#include <linux/list.h>
#include <linux/rcupdate.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <net/mac80211.h>
#include <asm/unaligned.h>
#include "ieee80211_i.h"
#include "driver-ops.h"
#include "debugfs_key.h"
#include "aes_ccm.h"
#include "aes_cmac.h"


/**
 * DOC: Key handling basics
 *
 * Key handling in mac80211 is done based on per-interface (sub_if_data)
 * keys and per-station keys. Since each station belongs to an interface,
 * each station key also belongs to that interface.
 *
 * Hardware acceleration is done on a best-effort basis for algorithms
 * that are implemented in software,  for each key the hardware is asked
 * to enable that key for offloading but if it cannot do that the key is
 * simply kept for software encryption (unless it is for an algorithm
 * that isn't implemented in software).
 * There is currently no way of knowing whether a key is handled in SW
 * or HW except by looking into debugfs.
 *
 * All key management is internally protected by a mutex. Within all
 * other parts of mac80211, key references are, just as STA structure
 * references, protected by RCU. Note, however, that some things are
 * unprotected, namely the key->sta dereferences within the hardware
 * acceleration functions. This means that sta_info_destroy() must
 * remove the key which waits for an RCU grace period.
 */

static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };

static void assert_key_lock(struct ieee80211_local *local)
{
	lockdep_assert_held(&local->key_mtx);
}

static void increment_tailroom_need_count(struct ieee80211_sub_if_data *sdata)
{
	/*
	 * When this count is zero, SKB resizing for allocating tailroom
	 * for IV or MMIC is skipped. But, this check has created two race
	 * cases in xmit path while transiting from zero count to one:
	 *
	 * 1. SKB resize was skipped because no key was added but just before
	 * the xmit key is added and SW encryption kicks off.
	 *
	 * 2. SKB resize was skipped because all the keys were hw planted but
	 * just before xmit one of the key is deleted and SW encryption kicks
	 * off.
	 *
	 * In both the above case SW encryption will find not enough space for
	 * tailroom and exits with WARN_ON. (See WARN_ONs at wpa.c)
	 *
	 * Solution has been explained at
	 * http://mid.gmane.org/1308590980.4322.19.camel@jlt3.sipsolutions.net
	 */

	if (!sdata->crypto_tx_tailroom_needed_cnt++) {
		/*
		 * Flush all XMIT packets currently using HW encryption or no
		 * encryption at all if the count transition is from 0 -> 1.
		 */
		synchronize_net();
	}
}

static int ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
{
	struct ieee80211_sub_if_data *sdata;
	struct sta_info *sta;
	int ret;

	might_sleep();

	if (key->flags & KEY_FLAG_TAINTED)
		return -EINVAL;

	if (!key->local->ops->set_key)
		goto out_unsupported;

	assert_key_lock(key->local);

	sta = key->sta;

	/*
	 * If this is a per-STA GTK, check if it
	 * is supported; if not, return.
	 */
	if (sta && !(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE) &&
	    !(key->local->hw.flags & IEEE80211_HW_SUPPORTS_PER_STA_GTK))
		goto out_unsupported;

	if (sta && !sta->uploaded)
		goto out_unsupported;

	sdata = key->sdata;
	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
		/*
		 * The driver doesn't know anything about VLAN interfaces.
		 * Hence, don't send GTKs for VLAN interfaces to the driver.
		 */
		if (!(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE))
			goto out_unsupported;
	}

	ret = drv_set_key(key->local, SET_KEY, sdata,
			  sta ? &sta->sta : NULL, &key->conf);

	if (!ret) {
		key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;

		if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
		      (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) ||
		      (key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)))
			sdata->crypto_tx_tailroom_needed_cnt--;

		WARN_ON((key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
			(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV));

		return 0;
	}

	if (ret != -ENOSPC && ret != -EOPNOTSUPP)
		sdata_err(sdata,
			  "failed to set key (%d, %pM) to hardware (%d)\n",
			  key->conf.keyidx,
			  sta ? sta->sta.addr : bcast_addr, ret);

 out_unsupported:
	switch (key->conf.cipher) {
	case WLAN_CIPHER_SUITE_WEP40:
	case WLAN_CIPHER_SUITE_WEP104:
	case WLAN_CIPHER_SUITE_TKIP:
	case WLAN_CIPHER_SUITE_CCMP:
	case WLAN_CIPHER_SUITE_AES_CMAC:
		/* all of these we can do in software */
		return 0;
	default:
		return -EINVAL;
	}
}

static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
{
	struct ieee80211_sub_if_data *sdata;
	struct sta_info *sta;
	int ret;

	might_sleep();

	if (!key || !key->local->ops->set_key)
		return;

	assert_key_lock(key->local);

	if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
		return;

	sta = key->sta;
	sdata = key->sdata;

	if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
	      (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) ||
	      (key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)))
		increment_tailroom_need_count(sdata);

	ret = drv_set_key(key->local, DISABLE_KEY, sdata,
			  sta ? &sta->sta : NULL, &key->conf);

	if (ret)
		sdata_err(sdata,
			  "failed to remove key (%d, %pM) from hardware (%d)\n",
			  key->conf.keyidx,
			  sta ? sta->sta.addr : bcast_addr, ret);

	key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
}

static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
					int idx, bool uni, bool multi)
{
	struct ieee80211_key *key = NULL;

	assert_key_lock(sdata->local);

	if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
		key = key_mtx_dereference(sdata->local, sdata->keys[idx]);

	if (uni) {
		rcu_assign_pointer(sdata->default_unicast_key, key);
		drv_set_default_unicast_key(sdata->local, sdata, idx);
	}

	if (multi)
		rcu_assign_pointer(sdata->default_multicast_key, key);

	ieee80211_debugfs_key_update_default(sdata);
}

void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
			       bool uni, bool multi)
{
	mutex_lock(&sdata->local->key_mtx);
	__ieee80211_set_default_key(sdata, idx, uni, multi);
	mutex_unlock(&sdata->local->key_mtx);
}

static void
__ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
{
	struct ieee80211_key *key = NULL;

	assert_key_lock(sdata->local);

	if (idx >= NUM_DEFAULT_KEYS &&
	    idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
		key = key_mtx_dereference(sdata->local, sdata->keys[idx]);

	rcu_assign_pointer(sdata->default_mgmt_key, key);

	ieee80211_debugfs_key_update_default(sdata);
}

void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
				    int idx)
{
	mutex_lock(&sdata->local->key_mtx);
	__ieee80211_set_default_mgmt_key(sdata, idx);
	mutex_unlock(&sdata->local->key_mtx);
}


static void ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
				  struct sta_info *sta,
				  bool pairwise,
				  struct ieee80211_key *old,
				  struct ieee80211_key *new)
{
	int idx;
	bool defunikey, defmultikey, defmgmtkey;

	/* caller must provide at least one old/new */
	if (WARN_ON(!new && !old))
		return;

	if (new)
		list_add_tail(&new->list, &sdata->key_list);

	WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);

	if (old)
		idx = old->conf.keyidx;
	else
		idx = new->conf.keyidx;

	if (sta) {
		if (pairwise) {
			rcu_assign_pointer(sta->ptk[idx], new);
			sta->ptk_idx = idx;
		} else {
			rcu_assign_pointer(sta->gtk[idx], new);
			sta->gtk_idx = idx;
		}
	} else {
		defunikey = old &&
			old == key_mtx_dereference(sdata->local,
						sdata->default_unicast_key);
		defmultikey = old &&
			old == key_mtx_dereference(sdata->local,
						sdata->default_multicast_key);
		defmgmtkey = old &&
			old == key_mtx_dereference(sdata->local,
						sdata->default_mgmt_key);

		if (defunikey && !new)
			__ieee80211_set_default_key(sdata, -1, true, false);
		if (defmultikey && !new)
			__ieee80211_set_default_key(sdata, -1, false, true);
		if (defmgmtkey && !new)
			__ieee80211_set_default_mgmt_key(sdata, -1);

		rcu_assign_pointer(sdata->keys[idx], new);
		if (defunikey && new)
			__ieee80211_set_default_key(sdata, new->conf.keyidx,
						    true, false);
		if (defmultikey && new)
			__ieee80211_set_default_key(sdata, new->conf.keyidx,
						    false, true);
		if (defmgmtkey && new)
			__ieee80211_set_default_mgmt_key(sdata,
							 new->conf.keyidx);
	}

	if (old)
		list_del(&old->list);
}

struct ieee80211_key *
ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
		    const u8 *key_data,
		    size_t seq_len, const u8 *seq,
		    const struct ieee80211_cipher_scheme *cs)
{
	struct ieee80211_key *key;
	int i, j, err;

	if (WARN_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS))
		return ERR_PTR(-EINVAL);

	key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
	if (!key)
		return ERR_PTR(-ENOMEM);

	/*
	 * Default to software encryption; we'll later upload the
	 * key to the hardware if possible.
	 */
	key->conf.flags = 0;
	key->flags = 0;

	key->conf.cipher = cipher;
	key->conf.keyidx = idx;
	key->conf.keylen = key_len;
	switch (cipher) {
	case WLAN_CIPHER_SUITE_WEP40:
	case WLAN_CIPHER_SUITE_WEP104:
		key->conf.iv_len = IEEE80211_WEP_IV_LEN;
		key->conf.icv_len = IEEE80211_WEP_ICV_LEN;
		break;
	case WLAN_CIPHER_SUITE_TKIP:
		key->conf.iv_len = IEEE80211_TKIP_IV_LEN;
		key->conf.icv_len = IEEE80211_TKIP_ICV_LEN;
		if (seq) {
			for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
				key->u.tkip.rx[i].iv32 =
					get_unaligned_le32(&seq[2]);
				key->u.tkip.rx[i].iv16 =
					get_unaligned_le16(seq);
			}
		}
		spin_lock_init(&key->u.tkip.txlock);
		break;
	case WLAN_CIPHER_SUITE_CCMP:
		key->conf.iv_len = IEEE80211_CCMP_HDR_LEN;
		key->conf.icv_len = IEEE80211_CCMP_MIC_LEN;
		if (seq) {
			for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
				for (j = 0; j < IEEE80211_CCMP_PN_LEN; j++)
					key->u.ccmp.rx_pn[i][j] =
						seq[IEEE80211_CCMP_PN_LEN - j - 1];
		}
		/*
		 * Initialize AES key state here as an optimization so that
		 * it does not need to be initialized for every packet.
		 */
		key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(key_data);
		if (IS_ERR(key->u.ccmp.tfm)) {
			err = PTR_ERR(key->u.ccmp.tfm);
			kfree(key);
			return ERR_PTR(err);
		}
		break;
	case WLAN_CIPHER_SUITE_AES_CMAC:
		key->conf.iv_len = 0;
		key->conf.icv_len = sizeof(struct ieee80211_mmie);
		if (seq)
			for (j = 0; j < IEEE80211_CMAC_PN_LEN; j++)
				key->u.aes_cmac.rx_pn[j] =
					seq[IEEE80211_CMAC_PN_LEN - j - 1];
		/*
		 * Initialize AES key state here as an optimization so that
		 * it does not need to be initialized for every packet.
		 */
		key->u.aes_cmac.tfm =
			ieee80211_aes_cmac_key_setup(key_data);
		if (IS_ERR(key->u.aes_cmac.tfm)) {
			err = PTR_ERR(key->u.aes_cmac.tfm);
			kfree(key);
			return ERR_PTR(err);
		}
		break;
	default:
		if (cs) {
			size_t len = (seq_len > MAX_PN_LEN) ?
						MAX_PN_LEN : seq_len;

			key->conf.iv_len = cs->hdr_len;
			key->conf.icv_len = cs->mic_len;
			for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
				for (j = 0; j < len; j++)
					key->u.gen.rx_pn[i][j] =
							seq[len - j - 1];
		}
	}
	memcpy(key->conf.key, key_data, key_len);
	INIT_LIST_HEAD(&key->list);

	return key;
}

static void ieee80211_key_free_common(struct ieee80211_key *key)
{
	if (key->conf.cipher == WLAN_CIPHER_SUITE_CCMP)
		ieee80211_aes_key_free(key->u.ccmp.tfm);
	if (key->conf.cipher == WLAN_CIPHER_SUITE_AES_CMAC)
		ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
	kzfree(key);
}

static void __ieee80211_key_destroy(struct ieee80211_key *key,
				    bool delay_tailroom)
{
	if (key->local)
		ieee80211_key_disable_hw_accel(key);

	if (key->local) {
		struct ieee80211_sub_if_data *sdata = key->sdata;

		ieee80211_debugfs_key_remove(key);

		if (delay_tailroom) {
			/* see ieee80211_delayed_tailroom_dec */
			sdata->crypto_tx_tailroom_pending_dec++;
			schedule_delayed_work(&sdata->dec_tailroom_needed_wk,
					      HZ/2);
		} else {
			sdata->crypto_tx_tailroom_needed_cnt--;
		}
	}

	ieee80211_key_free_common(key);
}

static void ieee80211_key_destroy(struct ieee80211_key *key,
				  bool delay_tailroom)
{
	if (!key)
		return;

	/*
	 * Synchronize so the TX path can no longer be using
	 * this key before we free/remove it.
	 */
	synchronize_net();

	__ieee80211_key_destroy(key, delay_tailroom);
}

void ieee80211_key_free_unused(struct ieee80211_key *key)
{
	WARN_ON(key->sdata || key->local);
	ieee80211_key_free_common(key);
}

int ieee80211_key_link(struct ieee80211_key *key,
		       struct ieee80211_sub_if_data *sdata,
		       struct sta_info *sta)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_key *old_key;
	int idx, ret;
	bool pairwise;

	pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
	idx = key->conf.keyidx;
	key->local = sdata->local;
	key->sdata = sdata;
	key->sta = sta;

	mutex_lock(&sdata->local->key_mtx);

	if (sta && pairwise)
		old_key = key_mtx_dereference(sdata->local, sta->ptk[idx]);
	else if (sta)
		old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]);
	else
		old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]);

	increment_tailroom_need_count(sdata);

	ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
	ieee80211_key_destroy(old_key, true);

	ieee80211_debugfs_key_add(key);

	if (!local->wowlan) {
		ret = ieee80211_key_enable_hw_accel(key);
		if (ret)
			ieee80211_key_free(key, true);
	} else {
		ret = 0;
	}

	mutex_unlock(&sdata->local->key_mtx);

	return ret;
}

void ieee80211_key_free(struct ieee80211_key *key, bool delay_tailroom)
{
	if (!key)
		return;

	/*
	 * Replace key with nothingness if it was ever used.
	 */
	if (key->sdata)
		ieee80211_key_replace(key->sdata, key->sta,
				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
				key, NULL);
	ieee80211_key_destroy(key, delay_tailroom);
}

void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_key *key;

	ASSERT_RTNL();

	if (WARN_ON(!ieee80211_sdata_running(sdata)))
		return;

	mutex_lock(&sdata->local->key_mtx);

	sdata->crypto_tx_tailroom_needed_cnt = 0;

	list_for_each_entry(key, &sdata->key_list, list) {
		increment_tailroom_need_count(sdata);
		ieee80211_key_enable_hw_accel(key);
	}

	mutex_unlock(&sdata->local->key_mtx);
}

void ieee80211_iter_keys(struct ieee80211_hw *hw,
			 struct ieee80211_vif *vif,
			 void (*iter)(struct ieee80211_hw *hw,
				      struct ieee80211_vif *vif,
				      struct ieee80211_sta *sta,
				      struct ieee80211_key_conf *key,
				      void *data),
			 void *iter_data)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_key *key, *tmp;
	struct ieee80211_sub_if_data *sdata;

	ASSERT_RTNL();

	mutex_lock(&local->key_mtx);
	if (vif) {
		sdata = vif_to_sdata(vif);
		list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
			iter(hw, &sdata->vif,
			     key->sta ? &key->sta->sta : NULL,
			     &key->conf, iter_data);
	} else {
		list_for_each_entry(sdata, &local->interfaces, list)
			list_for_each_entry_safe(key, tmp,
						 &sdata->key_list, list)
				iter(hw, &sdata->vif,
				     key->sta ? &key->sta->sta : NULL,
				     &key->conf, iter_data);
	}
	mutex_unlock(&local->key_mtx);
}
EXPORT_SYMBOL(ieee80211_iter_keys);

static void ieee80211_free_keys_iface(struct ieee80211_sub_if_data *sdata,
				      struct list_head *keys)
{
	struct ieee80211_key *key, *tmp;

	sdata->crypto_tx_tailroom_needed_cnt -=
		sdata->crypto_tx_tailroom_pending_dec;
	sdata->crypto_tx_tailroom_pending_dec = 0;

	ieee80211_debugfs_key_remove_mgmt_default(sdata);

	list_for_each_entry_safe(key, tmp, &sdata->key_list, list) {
		ieee80211_key_replace(key->sdata, key->sta,
				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
				key, NULL);
		list_add_tail(&key->list, keys);
	}

	ieee80211_debugfs_key_update_default(sdata);
}

void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata,
			 bool force_synchronize)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_sub_if_data *vlan;
	struct ieee80211_key *key, *tmp;
	LIST_HEAD(keys);

	cancel_delayed_work_sync(&sdata->dec_tailroom_needed_wk);

	mutex_lock(&local->key_mtx);

	ieee80211_free_keys_iface(sdata, &keys);

	if (sdata->vif.type == NL80211_IFTYPE_AP) {
		list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
			ieee80211_free_keys_iface(vlan, &keys);
	}

	if (!list_empty(&keys) || force_synchronize)
		synchronize_net();
	list_for_each_entry_safe(key, tmp, &keys, list)
		__ieee80211_key_destroy(key, false);

	WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
		     sdata->crypto_tx_tailroom_pending_dec);
	if (sdata->vif.type == NL80211_IFTYPE_AP) {
		list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
			WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
				     vlan->crypto_tx_tailroom_pending_dec);
	}

	mutex_unlock(&local->key_mtx);
}

void ieee80211_free_sta_keys(struct ieee80211_local *local,
			     struct sta_info *sta)
{
	struct ieee80211_key *key;
	int i;

	mutex_lock(&local->key_mtx);
	for (i = 0; i < ARRAY_SIZE(sta->gtk); i++) {
		key = key_mtx_dereference(local, sta->gtk[i]);
		if (!key)
			continue;
		ieee80211_key_replace(key->sdata, key->sta,
				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
				key, NULL);
		__ieee80211_key_destroy(key, true);
	}

	for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
		key = key_mtx_dereference(local, sta->ptk[i]);
		if (!key)
			continue;
		ieee80211_key_replace(key->sdata, key->sta,
				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
				key, NULL);
		__ieee80211_key_destroy(key, true);
	}

	mutex_unlock(&local->key_mtx);
}

void ieee80211_delayed_tailroom_dec(struct work_struct *wk)
{
	struct ieee80211_sub_if_data *sdata;

	sdata = container_of(wk, struct ieee80211_sub_if_data,
			     dec_tailroom_needed_wk.work);

	/*
	 * The reason for the delayed tailroom needed decrementing is to
	 * make roaming faster: during roaming, all keys are first deleted
	 * and then new keys are installed. The first new key causes the
	 * crypto_tx_tailroom_needed_cnt to go from 0 to 1, which invokes
	 * the cost of synchronize_net() (which can be slow). Avoid this
	 * by deferring the crypto_tx_tailroom_needed_cnt decrementing on
	 * key removal for a while, so if we roam the value is larger than
	 * zero and no 0->1 transition happens.
	 *
	 * The cost is that if the AP switching was from an AP with keys
	 * to one without, we still allocate tailroom while it would no
	 * longer be needed. However, in the typical (fast) roaming case
	 * within an ESS this usually won't happen.
	 */

	mutex_lock(&sdata->local->key_mtx);
	sdata->crypto_tx_tailroom_needed_cnt -=
		sdata->crypto_tx_tailroom_pending_dec;
	sdata->crypto_tx_tailroom_pending_dec = 0;
	mutex_unlock(&sdata->local->key_mtx);
}

void ieee80211_gtk_rekey_notify(struct ieee80211_vif *vif, const u8 *bssid,
				const u8 *replay_ctr, gfp_t gfp)
{
	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);

	trace_api_gtk_rekey_notify(sdata, bssid, replay_ctr);

	cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp);
}
EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify);

void ieee80211_get_key_tx_seq(struct ieee80211_key_conf *keyconf,
			      struct ieee80211_key_seq *seq)
{
	struct ieee80211_key *key;
	u64 pn64;

	if (WARN_ON(!(keyconf->flags & IEEE80211_KEY_FLAG_GENERATE_IV)))
		return;

	key = container_of(keyconf, struct ieee80211_key, conf);

	switch (key->conf.cipher) {
	case WLAN_CIPHER_SUITE_TKIP:
		seq->tkip.iv32 = key->u.tkip.tx.iv32;
		seq->tkip.iv16 = key->u.tkip.tx.iv16;
		break;
	case WLAN_CIPHER_SUITE_CCMP:
		pn64 = atomic64_read(&key->u.ccmp.tx_pn);
		seq->ccmp.pn[5] = pn64;
		seq->ccmp.pn[4] = pn64 >> 8;
		seq->ccmp.pn[3] = pn64 >> 16;
		seq->ccmp.pn[2] = pn64 >> 24;
		seq->ccmp.pn[1] = pn64 >> 32;
		seq->ccmp.pn[0] = pn64 >> 40;
		break;
	case WLAN_CIPHER_SUITE_AES_CMAC:
		pn64 = atomic64_read(&key->u.aes_cmac.tx_pn);
		seq->ccmp.pn[5] = pn64;
		seq->ccmp.pn[4] = pn64 >> 8;
		seq->ccmp.pn[3] = pn64 >> 16;
		seq->ccmp.pn[2] = pn64 >> 24;
		seq->ccmp.pn[1] = pn64 >> 32;
		seq->ccmp.pn[0] = pn64 >> 40;
		break;
	default:
		WARN_ON(1);
	}
}
EXPORT_SYMBOL(ieee80211_get_key_tx_seq);

void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
			      int tid, struct ieee80211_key_seq *seq)
{
	struct ieee80211_key *key;
	const u8 *pn;

	key = container_of(keyconf, struct ieee80211_key, conf);

	switch (key->conf.cipher) {
	case WLAN_CIPHER_SUITE_TKIP:
		if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
			return;
		seq->tkip.iv32 = key->u.tkip.rx[tid].iv32;
		seq->tkip.iv16 = key->u.tkip.rx[tid].iv16;
		break;
	case WLAN_CIPHER_SUITE_CCMP:
		if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
			return;
		if (tid < 0)
			pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
		else
			pn = key->u.ccmp.rx_pn[tid];
		memcpy(seq->ccmp.pn, pn, IEEE80211_CCMP_PN_LEN);
		break;
	case WLAN_CIPHER_SUITE_AES_CMAC:
		if (WARN_ON(tid != 0))
			return;
		pn = key->u.aes_cmac.rx_pn;
		memcpy(seq->aes_cmac.pn, pn, IEEE80211_CMAC_PN_LEN);
		break;
	}
}
EXPORT_SYMBOL(ieee80211_get_key_rx_seq);

void ieee80211_set_key_tx_seq(struct ieee80211_key_conf *keyconf,
			      struct ieee80211_key_seq *seq)
{
	struct ieee80211_key *key;
	u64 pn64;

	key = container_of(keyconf, struct ieee80211_key, conf);

	switch (key->conf.cipher) {
	case WLAN_CIPHER_SUITE_TKIP:
		key->u.tkip.tx.iv32 = seq->tkip.iv32;
		key->u.tkip.tx.iv16 = seq->tkip.iv16;
		break;
	case WLAN_CIPHER_SUITE_CCMP:
		pn64 = (u64)seq->ccmp.pn[5] |
		       ((u64)seq->ccmp.pn[4] << 8) |
		       ((u64)seq->ccmp.pn[3] << 16) |
		       ((u64)seq->ccmp.pn[2] << 24) |
		       ((u64)seq->ccmp.pn[1] << 32) |
		       ((u64)seq->ccmp.pn[0] << 40);
		atomic64_set(&key->u.ccmp.tx_pn, pn64);
		break;
	case WLAN_CIPHER_SUITE_AES_CMAC:
		pn64 = (u64)seq->aes_cmac.pn[5] |
		       ((u64)seq->aes_cmac.pn[4] << 8) |
		       ((u64)seq->aes_cmac.pn[3] << 16) |
		       ((u64)seq->aes_cmac.pn[2] << 24) |
		       ((u64)seq->aes_cmac.pn[1] << 32) |
		       ((u64)seq->aes_cmac.pn[0] << 40);
		atomic64_set(&key->u.aes_cmac.tx_pn, pn64);
		break;
	default:
		WARN_ON(1);
		break;
	}
}
EXPORT_SYMBOL_GPL(ieee80211_set_key_tx_seq);

void ieee80211_set_key_rx_seq(struct ieee80211_key_conf *keyconf,
			      int tid, struct ieee80211_key_seq *seq)
{
	struct ieee80211_key *key;
	u8 *pn;

	key = container_of(keyconf, struct ieee80211_key, conf);

	switch (key->conf.cipher) {
	case WLAN_CIPHER_SUITE_TKIP:
		if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
			return;
		key->u.tkip.rx[tid].iv32 = seq->tkip.iv32;
		key->u.tkip.rx[tid].iv16 = seq->tkip.iv16;
		break;
	case WLAN_CIPHER_SUITE_CCMP:
		if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
			return;
		if (tid < 0)
			pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
		else
			pn = key->u.ccmp.rx_pn[tid];
		memcpy(pn, seq->ccmp.pn, IEEE80211_CCMP_PN_LEN);
		break;
	case WLAN_CIPHER_SUITE_AES_CMAC:
		if (WARN_ON(tid != 0))
			return;
		pn = key->u.aes_cmac.rx_pn;
		memcpy(pn, seq->aes_cmac.pn, IEEE80211_CMAC_PN_LEN);
		break;
	default:
		WARN_ON(1);
		break;
	}
}
EXPORT_SYMBOL_GPL(ieee80211_set_key_rx_seq);

void ieee80211_remove_key(struct ieee80211_key_conf *keyconf)
{
	struct ieee80211_key *key;

	key = container_of(keyconf, struct ieee80211_key, conf);

	assert_key_lock(key->local);

	/*
	 * if key was uploaded, we assume the driver will/has remove(d)
	 * it, so adjust bookkeeping accordingly
	 */
	if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
		key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;

		if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
		      (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) ||
		      (key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)))
			increment_tailroom_need_count(key->sdata);
	}

	ieee80211_key_free(key, false);
}
EXPORT_SYMBOL_GPL(ieee80211_remove_key);

struct ieee80211_key_conf *
ieee80211_gtk_rekey_add(struct ieee80211_vif *vif,
			struct ieee80211_key_conf *keyconf)
{
	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_key *key;
	int err;

	if (WARN_ON(!local->wowlan))
		return ERR_PTR(-EINVAL);

	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
		return ERR_PTR(-EINVAL);

	key = ieee80211_key_alloc(keyconf->cipher, keyconf->keyidx,
				  keyconf->keylen, keyconf->key,
				  0, NULL, NULL);
	if (IS_ERR(key))
		return ERR_CAST(key);

	if (sdata->u.mgd.mfp != IEEE80211_MFP_DISABLED)
		key->conf.flags |= IEEE80211_KEY_FLAG_RX_MGMT;

	err = ieee80211_key_link(key, sdata, NULL);
	if (err)
		return ERR_PTR(err);

	return &key->conf;
}
EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_add);